<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>文件上传</title>
</head>

<body>
  <form action="http://localhost:1233/aaa" method="POST" enctype="multipart/form-data">
    用户名：<input type="text" name="username"><br>
    密码：<input type="password" name="pass"><br>
    文件<input type="file" name="file"><br>
    <input type="submit" value="提交">
  </form>

</body>

</html>